雅思听力

🎧 Listening Transcript

Today in our environmental science lecture, we'll discuss urban heat islands. Cities tend to be warmer than surrounding rural areas because concrete and asphalt absorb and re-emit heat more than vegetation does. One key solution is increasing green spaces, such as parks and green roofs. However, a recent study in a mid-sized city found that while parks reduce local temperatures by up to 2 degrees Celsius, green roofs have a smaller effect, mainly because they are often limited in size. The study also highlighted that planting street trees is more cost-effective than building underground cooling systems, which are expensive to maintain.